Surface modification of carbon fiber cloth with graphene oxide through an electrophoresis method for lithium metal anode

Abstract

Due to its woven structure, rich inner voids and high electrical conductivity, carbon fiber cloth (CFC) is considered as a promising three-dimensional (3D) current collector for lithium metal anode. However, it is usually inevitable that metallic Li plates on top of CFC as Li ions are instantaneously reduced when they reach the upper surface of CFC, which impedes the utilization of the inner space of CFC for accommodating Li deposition and causes poor cyclic stability of Li anode. In this study, by decorating a thin layer of graphene oxide (GO) on the surface of CFC using an electrophoresis method, an all-carbon 3D current collector with electrical conductivity differences in the vertical direction is fabricated. The graphene oxide layer with poor electrical conductivity induces downward electroplating of metallic Li into the inner voids of CFC, which fully exploits the effect of CFC as a 3D current collector in governing the plating/stripping behaviors of Li. As a result, the full cell using the GO modified CFC as the negative electrode and NCM811 positive electrodes can maintain 80% of its initial capacity after 460 cycles at a high current of 0.5C charge and 1C discharge.